<p>&nbsp;<font face="Arial"><font size="2"><strong>Capture of terms through an authority file or by using terminology previously entered into the database.</strong></font></font></p>
<p><font face="Arial"><font size="2">Through this option terms can be captured by using another database, for example, an authority database, or by using the same database, in order to standardise the authors, descriptors, editors, etc.<br />
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<p><font face="Arial"><font size="2">Access to the associated database of terms is made through the inverted list. Consequently sub-dictionaries must be defined inside the terms dictionary, by means of the prefixes to the indexed fields.<br />
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<p><font face="Arial"><font size="2">Through the prefix indicated in the FDT you can access the postings of the key, obtaining the Mfn of the record. The MFN of the first key posting is used to access the record, after which two formats are applied: &nbsp; <br />
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<ul>
    <li><strong><font size="2"><font face="Arial">display format</font></font></strong></li>
    <li><font face="Arial"><font face="Arial"><font size="2"><strong>extraction</strong></font></font> <font size="2"><strong>format </strong></font></font></li>
</ul>
<p><font size="2"><font face="Arial">The <strong>display format</strong> is applied to the record obtained through the posting in order to  determine how the format will be displayed in the field selection list being displayed to the user, while the <strong>extraction format</strong> is used to extract the field and transfer it to the record. The list is built with the element &lt;select&gt; from  HTML language and the options of the selection menu are completed as shown below:<br />
&lt;option value="</font></font><font face="Arial"><font face="Arial"><font size="2"><strong>extraction</strong></font></font> <font size="2"><strong>format</strong>"&gt;</font></font><strong><font size="2"><font face="Arial">display format</font></font></strong><font size="2"><font face="Arial">&lt;/option&gt;</font></font></p>
<p><font face="Arial"><font size="2">Then, when the user clicks on a term, the link associated with the <strong>extraction format</strong>  is transferred to the record.</font><br />
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The formats mentioned can have all the complexity of the format language for the construction of CDS/Isis. For very complicated formats, placing a previously built format as the extraction format (PFT) is recommended, using the form @xxxxxx.pft  to incorporate the format where it is required.&nbsp;In this case the extraction format and the display format are included in the @xxxxxx.pft format, separated with $$$. The </font><font size="2"><font face="Arial"> <strong>select</strong> </font></font> <font face="Arial">statement from the formatting language should be used to apply the format accurately to the ID of the recovered </font><font size="2"><font face="Arial">field</font></font> <font face="Arial">in the inverted list.<br />
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Example:<br />
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<p dir="ltr" style="MARGIN-RIGHT: 0px"><font face="Arial" size="2"><font face="Courier New">select e3<br />
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; case 1:&nbsp;&nbsp; v1<br />
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; case 100: v100^a,`$$$`v100^a<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case 600: v600^a,`$$$`v600^a<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case 700: v700^a,`$$$`v700^a</font></font><font face="Arial"><font face="Courier New"><br />
<font size="2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case 110: v110^a,`$$$`v110<br />
&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; case 111: v111^a,`$$$`v111<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case 245: v245^a,`$$$`f(mfn,1,0)<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case 260: v260^a," : "v260^b,</font></font></font><font face="Arial"><font face="Courier New" size="2">`$$$`v260</font></font><br />
<font face="Arial" size="2"><font face="Courier New">&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; case 270: v270<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; case 340: v340<br />
...<br />
<br />
...<br />
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endsel</font></font></p>
<p><font face="Arial" size="2">The variable associated to the case, identifies the ID allocated to the field in the FST; then the format to be used for the display of the field in the selection list is specified and next, preceded by '$$$', the format used to display the field and to transfer it to the input form. If the extraction format is omitted, the display format is used as an extraction format.</font></p>
<p><font size="2">The field ID is retrieved through the posting obtained by using the prefix. Therefore, it is possible to display a selection list that includes several fields, for example, all the personal authors of the Marc format&nbsp;(100,600,700).</font></p>
<p><font size="2">In this case, all the fields will be indexed with the same prefix, but the ID should be the same as the field tag for correct extractions from the data base, when applying the corresponding extraction format.</font></p>
<p><font size="2">For example, </font><font size="2"> according to the extraction format (@xxxxx.pft) previously shown, to display all the authors in MARC format, &nbsp;the FST for the indexing will specify:</font></p>
<p><font size="2">100 0 "AU_"v100^a/<br />
<font size="2">600 0 (| AU_| v600^a|%|/)<br />
<font size="2">700 0 (| AU_| v700^a|%|/)</font></font></font></p>
<p><font size="2">Note the usage of the % in the case of repeatable fields to generate the number of occurrences, since the presentation of the lists uses the posting component to identify the number of occurrences used to extract the field correctly.</font></p>
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